This invention relates to an electrophotographic photoreceptor wherein an .alpha.-form copper phthalocyanine composition composed of a copper tetranitrophthalocyanine and copper phthalocyanine having a specific structure, and a photoconductive squarylium compound are used as a photoconductive material.
Electrophotographic photoreceptors presently used are mostly of a functionally separating type containing a charge generation material having photosensitivity at a wavelength of a light source and a charge transport material having a high charge transport rate. The charge generation material is a photoconductive material, such as an azo pigment, a perylene pigment or a phthalocyaninc pigment or the like, and the charge transport material is a hydrazone compound, a styryl compound, a pyrazoline compound, a triphenylamine compound or the like.
On the other hand, there are single layer-type photoreceptors wherein a pigment having photosensitivity at a wavelength of a light source is dispersed in a binder resin, and the photoconductive material is an azo pigment, a quinacridone pigment, a perylene pigment, an anthraquinone pigment, a phthalocyanine pigment or the like.
The above photoreceptors using copper phthalocyanine as the photoconductive material have some problems, such as low sensitivity or sensitivity deviation or decrease in charge acceptance caused by repeated use.
Besides, due to the variety of information, it has been required to express copiers and printers not in monochromatic but multi or full color. There are some means to express a full color in electrophotographic processes. In the case of using filters or toners as the filters, a photoreceptor is necessary to be a panchromatic one having a sensitivity over the whole visible light region. However, no photoreceptor has been completed yet which satisfies both spectral sensitivity and light decay rate.